And thanks Scott Falkner, your suggestion works.
We know that you want to edit the settings of your previously applied effects.
What I said was that if you accidentally use the same Effect command twice, the application warns you that it would apply a second effect which is probably not what you want to do, and tells you that if you want to edit the options of the first effect, you should do what Scott suggested instead. (Sometimes applying a second effect really is wanted, but usually not, which is why there is the warning, complete with instructions about how to use the Appearance palette to edit the options of the previously applied effect.)